Method of making aluminum fluosilicate.



- following is a specification.

. ferred embodiment I mix powdered kaolin NITE EDWARD F. KERN, OE KNOXVILLE, TENNESSEE, ASSIGNOR OF ONE-HALF T0 PERCY S. BROWN, OF NEW YORK, N. Y.

METHOD OF MAKING ALUMINUM FLUOSILIC ATE.

No Drawing.

Patented July 5, 1910.

To all whom it mag concern:

Be it known that I, EDWARD F. KERN, a citizen of the United States, residing at Knoxville, in the county of Knox and State of Tennessee, have invented certain new and useful Improvements in Methods of Produc-v ing Aluminum Fluosilicate, of which the This invention relates to the preparation of fiuo-silicates, and has particular reference to the production of aluminum fluo-silicate (Al,(S1F,)3).-

Heretofore aluminum fluosilicat'e has been chiefly produced by the addition of fluosilicic acid to freshly precipitated aluminum hydrate. Aluminum fluo-silicate produced in this way is expensive by reason of the cost of the acid used in dissolving the aluminum from which the hydrate is made and the cost of the ammonia used in precipitating the aluminum in the form of the hydrate.

I have discovered that aluminum fluosilicate can be readily, cheaply and rapidly obtained direct from silicate of aluminum and particularly from kaolin.

In the practice of my process, in its preand silica in approximately molecular proportions and to this is added hydrofluoric acid in approximately molecular proportions as indicated by the following reaction;

The kaolin is first mixed v 3th water in order to reventtoo rapid reaction which would brmg about a loss of acid and the hydrofluoric acid is poured slowly over the mass of kaolin and silica. The temperature at which the hydrofluoric acid reacts with the mixture of kaolin and silica is preferably between atmos heric temperature and the boiling point 0 the acid, the latter being a ture for the reaction is plo e flue-silicate which consists in in presence 0 solution of hydrofluoric acid gas in water.

The reaction produces suflicient heat to cause tho solution to boil. The referred temperaelow the boiling point, preferably between 50 and 70 degrees At a higher temperature some acid is lost by vaporization. The amount of water may be varied as desired, satisfactory results being obtained when suflicient water is added to form a pasty mass with the kaolin and silica.

While I have illustrated my invention as embodyin the use of kaolin it is to be understood t at any aluminum silicate or any hgdrated aluminum silicate may be emaving described my invention, I claim- 1. The process of preparing aluminum fluo-silicate which consists in reacting upon aluminum silicate and oxid of silicon with hydrofluoric acid.

2. The process of preparing aluminum fluo-silicate which conslsts in mixing aluminum silicate and silica and adding hydrofluoric acid thereto.

3. The process of preparing aluminum fluo-silicate which consists in mlxing aluminum silicate, silica and water and adding hydrofluoric acid thereto. 4. The process of preparing aluminum flue-silicate which consists in mlxing aluminum silicate, silica and hydrofluoric acid in approximately molecular proportions.

5. The process of preparin aluminum mixing aluminum silicate, silica and hydrofluoric acid in approximately molecular proportions in the presence of water.

In testimon whereof I aflix my signature two witnesses.

EDWARD F. KERN.

Witnesses:

FREDERIG W. Ems, ADELE M. EBB. 

